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Biomedical subjects

B Buis

Publications and source records attributed to B Buis.

35 records · Page 2Linked to original sources
PubMed1987

Unclassified familial cardiomyopathy with ventricular dysrhythmia.

The case is described of a boy with some right ventricular dysplasia and episodes of ventricular tachycardia of left bundle branch block pattern who had symptoms from the age of 1 month. Angiography and cardiac biopsy demonstrated major involvement of the left ventricular myocardium. A sister of the patient presented at the age of 2 months with predominantly left ventricular cardiomyopathy; clinical signs and angiography suggested the presence of right ventricular dysplasia as well. She died suddenly at the age of 9 years. Her brother, now aged 14 years, is being treated with antiarrhythmic drugs. The hypothesis of this cardiomyopathy being a variant of "arrhythmogenic right ventricular dysplasia syndrome" is discussed.

Bundle-Branch Block↗
PubMed1987

Association of cholesterol concentrations in low-density lipoprotein, high-density lipoprotein, and high-density lipoprotein subfractions, and of apolipoproteins AI and AII, with coronary stenosis and left ventricular function.

We examined the association of cholesterol levels in serum lipoprotein fractions, as well as of serum apolipoprotein-AI (apo-AI) and apo-AII levels, with coronary artery stenosis (CAS) and left ventricle function in a group of 43 patients with angina pectoris (33 men and 10 women) subjected to angiography. Cholesterol level in VLDL, LDL, HDL2, and HDL3 fractions was determined after separation of these fractions by density gradient ultracentrifugation. HDL-cholesterol is the sum of cholesterol in HDL2 and HDL3. Cineangiography yielded scores for CAS and for left ventricle ejection fraction (LVEF). On univariate regression CAS was correlated weakly with LDL-cholesterol (positive) and with HDL3-cholesterol and HDL-cholesterol (negative), and more strongly with LDL-cholesterol/HDL-cholesterol (positive), but not with HDL2-cholesterol. LVEF was correlated positively with HDL3-cholesterol, HDL-cholesterol, apo-AI, and apo-AII. Of other "risk factors," none was correlated with CAS, and a history of previous myocardial infarction (PMI) was the only one significantly correlated with LVEF. CAS itself was also correlated negatively with LVEF. In multiple regression analysis with two or three independent variables, the relation of HDL(3)-cholesterol with CAS remained significant when other risk factors were taken into account. LVEF remained related positively with HDL(3)-cholesterol, apo-AI, or apo-AII, when either of them was tested in combination with other risk factors; of these only PMI made a significant independent contribution. Conclusions for this patient group (with low HDL-cholesterol): HDL3-cholesterol, and not HDL2-cholesterol, is informative for CAS; HDL(3)-cholesterol, apo-AI, or apo-AII, as well as CAS and PMI, are associated with LVEF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Diet, lipoproteins, and the progression of coronary atherosclerosis. The Leiden Intervention Trial.

We studied the relation between diet, serum lipoproteins, and the progression of coronary lesions in 39 patients with stable angina pectoris in whom coronary arteriography had shown at least one vessel with 50 per cent obstruction before intervention. Intervention consisted of a two-year vegetarian diet that had a ratio of polyunsaturated to saturated fatty acids of at least 2 and that contained less than 100 mg of cholesterol per day. Dietary changes were associated with a significant increase in linoleic acid content of cholesteryl esters and a significant lowering of body weight, systolic blood pressure, serum total cholesterol, and the ratio of total to high-density lipoprotein (total/HDL) cholesterol. Angiographic examination was performed after 24 months; angiograms were assessed visually (with blinding) and by computer-assisted image analysis. Both types of assessment indicated progression of disease in 21 of 39 patients but no lesion growth in 18. Coronary lesion growth correlated with total/HDL cholesterol (r = 0.50, P = 0.001) but not with blood pressure, smoking status, alcohol intake, weight, or drug treatment. Disease progression was significant in patients who had values for total/HDL cholesterol that were higher than the median (greater than 6.9) throughout the trial period. No coronary-lesion growth was observed in patients who had lower values for total/HDL cholesterol (less than 6.9) throughout the trial or who initially had higher values (greater than 6.9) that were significantly lowered by dietary intervention.

Adult↗
PubMed1984

A comparative study on enzymatic data from myocardial biopsies and cardiac function in patients who underwent cardiac surgery.

Twenty-three patients underwent cardiac surgery for valve replacement, valve reconstruction, aorto-coronary bypass grafting, aneurysmectomy or combinations of these. Excised cardiac tissue was obtained from left ventricular (LV) papillary muscle (17 patients), LV outflow tract (3 patients), or LV aneurysms (3 patients). A total of 34 myocardial samples, collected from excised cardiac tissue, were analysed for creatine kinase (CK), CK-isoenzymes, cytoplasmic and mitochondrial isoenzymes of aspartate aminotransferase (cAST and mAST, respectively), and lactate dehydrogenase (LDH) isoenzymes. Myocardial CK activity correlated positively with preoperative LV ejection fraction (p less than 0.001), negatively with the preoperatively measured extent of LV wall motion abnormalities (p less than 0.001), and negatively with preoperative LVEDP (p less than 0.02). Myocardial CK activity was negatively correlated with preoperative validity class (p less than 0.005). However, no correlation existed between myocardial CK activity and postoperative validity. Excluding the biopsies from LV aneurysms, myocardial CK activity was positively correlated with the fraction H-subunits in LDH (p = 0.02), and was negatively correlated with the fraction mAST in total AST (p less than 0.005). While cAST activity was proportional to CK activity in the biopsies from VL papillary muscle and LV outflow tract, mAST activity declined only with 2.4 +/- 1.2% per 10% fall of CK. The increase of mAST/cAST ratio with decreasing CK, together with the decrease of LDH-H/LDH and CK-M/CK ratios with decreasing CK, indicated the presence of an adaptation process in a myocardium with low CK activity rather than a process of necrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Cholesterol embolism as a complication of left heart catheterisation. Report of seven cases.

Cholesterol embolism after left heart catheterisation by the femoral approach was diagnosed in seven men (mean age 59.6 years) out of a total of 4587 catheterisations. Diabetes was present in four patients, systemic hypertension in three, and signs of extensive atherosclerosis in six; five patients were taking anticoagulant drugs. Acute pain in the legs or abdomen occurred in six patients, two of whom had abdominal angina; renal failure was present in six patients, cutaneous manifestations in five, and a cholesterol embolus was seen in the retina in one. Six out of six patients had an appreciable increase in the erythrocyte sedimentation rate and five out of five had eosinophilia within a week of catheterisation. Renal failure was progressive in five patients, one of whom required haemodialysis. Three patients required amputation of the toes because of gangrene. Four patients died within four and a half months of catheterisation from causes not directly related to cholesterol embolism. At necropsy cholesterol emboli were found in all four patients. Cholesterol embolism is a rare but serious complication of left heart catheterisation.

Aged↗
PubMed1984

Continuous measurement of left ventricular volume in animals and humans by conductance catheter.

An eight-electrode conductance catheter previously developed by us and used to determine stroke volume in dogs was applied in human beings and dogs to measure absolute left ventricular volume quantitatively. For calibration we developed the formula V(t) = (1/alpha)(L2/sigma b)G(t) - Vc, where V(t) is time-varying left ventricular volume, alpha is a dimensionless constant, L is the electrode separation, sigma b is the conductivity of blood obtained by a sampling cuvette, and G(t) is the measured conductance within the left ventricular cavity. Vc is a correction term caused by the parallel conductance of structures surrounding the cavity and is measured in two ways. The first method, applicable in the anesthetized animal, consists of temporary reduction of volume to zero by suction. The second method uses a transient change in sigma b by injection of a small bolus of hypertonic saline (dogs) or 10 ml of cold glucose (humans) into the pulmonary artery. The validity of the formula was previously established for the isolated postmortem canine heart. The predicted linearity, slope constant alpha, and accuracy of Vc for the left ventricle in vivo were investigated by comparing the conductance volume data with results from independent methods: electromagnetic blood flow measurement for stroke volume and indicator dilution technique for ejection fraction (dogs), thermal dilution for cardiac output (12 patients), and single-plane cineventriculography for V(t) (five patients). In all comparisons, linear regression showed high correlation (from r = .82 [n = 46] to r = .988 [n = 20]) while alpha, with one exception, ranged from 0.75 to 1.07 and the error in Vc ranged from 0.5% to 16.5% (mean 7%). After positioning of the catheter, no arrhythmias were observed. It is concluded that the conductance catheter provides a reliable and simple method to measure left ventricular volume, giving an on-line, time-varying signal that is easily calibrated. Together with left ventricular pressure obtained through the catheter lumen, the instrument may be used for instantaneous display of pressure-volume loops to facilitate assessment of left ventricular pump performance.

Animals↗
PubMed1981

Relations between ejection fraction and ventricular volume, and their alteration by chronic beta-blockade.

This study describes the newly discovered relation between ejection fraction and end-systolic volume index (ESVI) of the left ventricle as obtained by angiography at the time of cardiac catheterisation. Linear regression analysis shows that ejection fraction (%)=82.0-0.62 ESVI (ml/m2) but the correlation for patients receiving beta-adrenergic blocking drugs is significantly lower compared with the untreated group. Non-linear analysis, applied to cover also the asymptotic range for ejection fraction less than 20%, shows similar results. The good relation between the two indices indicates that the index ejection fraction may derive its clinical importance directly from the more fundamental index end-systolic volume index by virtue of the operation of the beta-adrenergic system on the heart.

Adrenergic beta-Antagonists↗
PubMed1975

Coronary arterial mapping in hypertrophic cardiomyopathy.

The diameters of the coronary arteries and their peripheral branches were measured on coronary angiograms obtained from 9 patients with hypertrophic obstructive cardiomyopathy (HOCM), 6 patients with hypertrophic non-obstructive cardiomyopathy, and 6 normal controls. There was a marked increase in the diameters of the main coronary arteries in the patients suffering from cardiomyopathy but no significant difference in the peripheral branches between the three groups. This discrepancy between the 'run-in' and 'run-off' components of coronary circulation could explain anginal symptoms during exercise in HOCM, but in the absence of direct coronary flow measurements this theory remains to be tested. HOCM was associated with the widest arteries whereas hypertrophic non-obstructive cardiomyopathy occupied an intermediate position between HOCM and the control group.

Cardiac Catheterization↗
PubMedDate not supplied

Comparative trial of Omnipaque 350 (iohexol) and Telebrix 350 (sodium-meglumine-ioxithalamate) in left ventriculography and coronary arteriography.

In a double-blind randomized trial, the hemodynamic and electrophysiologic effects of the low-osmolar nonionic contrast medium iohexol (Omnipaque) and the standard high-osmolar ionic monomer sodium-meglumine-ioxithalamate (Telebrix) at left ventricular angiography and selective coronary arteriography were evaluated. Sixty patients were divided into two groups of 30 patients; one group received Omnipaque in a dosage of 350 mgI/ml and the other group received Telebrix in a dosage of 350 mgI/ml. The Omnipaque showed significantly less effects on heart rate and myocardial contractility, and induced less electrophysiological changes than did Telebrix. However, there was a significant increase of 10% in the diameter of the left coronary artery following selective coronary injection with Telebrix, while Omnipaque induced practically no change in vessel diameter. All hemodynamic and electrophysiologic effects proved to be short-lasting. We conclude that ionic and nonionic agents are similarly efficacious in providing adequate images with minimal risk to the patient. However, the nonionic agents exert slightly more alterations in cardiac hemodynamics and in electrocardiographic intervals. The vasodilatory effect on coronary artery diameter by Telebrix may entail a more rapid clearance of contrast medium from the coronary circulation, which might be of some advantage over nonionic contrast media.

Aged↗
PubMedDate not supplied

Three-dimensional densitometric reconstruction and visualization of stenosed coronary artery segments.

In this paper we report results from an ongoing study about the diagnostic benefits of three-dimensional (3D) visualization and quantification of stenosed coronary artery segments. Biplane angiographic images do not provide enough information for the exact reconstruction of the coronary arteries. Therefore, a priori information about the 3D shape to be reconstructed must be incorporated into the reconstruction algorithm. One approach is to assume a circular cross-section of the coronary artery. Hence, the diameter is estimated from the contours of the vessel in both projections. Another approach is based on densitometry and searches for a solution of the reconstruction problem close to the previously reconstructed adjacent slice. In this paper we apply contour information as well as the densitometrical profiles of the two orthogonal vessel projections. We present a new probabilistic densitometric reconstruction algorithm, which extends the correct handling of the stochastic properties of the density profiles into the network flow based reconstruction algorithm. The reconstructed coronary segment is visualized in three dimensions. In order to assess the accuracy of the reconstruction, the method is applied to tubes with artificial obstruction of known geometry, modeling coronary artery stenoses. These catheter tubes are filled with normal iodine contrast material. The results of the reconstruction and visualization are discussed with respect to clinical usefulness.

Absorptiometry, Photon↗
PubMedDate not supplied

IgG subclasses in CAPD patients.

OBJECTIVE: To make a comparison of serum levels of immunoglobulin G (IgG) subclasses in adult continuous ambulatory peritoneal dialysis (CAPD) patients with those in age- and sex-matched hemodialysis patients and healthy volunteers, and to analyze the contribution of removal of these proteins in peritoneal effluent to their plasma values. DESIGN: A cross-sectional study. SETTING: A renal unit of a university hospital. PATIENTS: Twenty-three CAPD patients, 21 hemodialysis patients, and 21 healthy volunteers. Peritoneal transport studies were done in 8 of the 23 CAPD patients. METHODS: IgG subclasses were measured in serum by nephelometry. For the peritoneal transport studies an ELISA method on ethylenediamine tetracetic acid plasma was used. The same method was used in seven-to-ten-fold concentrated peritoneal dialysate. RESULTS: CAPD patients had lower IgG2 and IgG4 levels than hemodialysis patients and healthy volunteers (p < 0.01). IgG2 values below 1.5 g/L were present in 43% of the CAPD patients (p < 0.001 compared to healthy volunteers). Peritonitis incidence was not different between CAPD patients with low or normal IgG2 plasma levels. Peritoneal clearance of IgG3 was lower than that of the other subclasses. Evidence was obtained for a depressed synthesis of IgG2 and IgG4 in CAPD patients. The hypothesis that interleukin-2 may be involved in the low synthesis rate of IgG2 is discussed. CONCLUSION: Low serum IgG2 and IgG4 levels are present in stable, adult CAPD patients. These were not caused by increased peritoneal loss, but by decreased synthesis.

Adult↗